I also used to religiously target C89 for "maximum compatibility" (`-ansi -pedantic`). But the problem with this approach is that it's 2021, and C89 doesn't hav

I also used to religiously target C89 for "maximum compatibility" (`-ansi -pedantic`). But the problem with this approach is that it's 2021, and C89 doesn't have a concurrency model. FFS, use C11 or newer. Even if you're writing for consoles and weird microcontrollers, the compilers have mostly caught up.